It has been known to perform drawing operations on various shapes of open-sided channel members by pulling a channel through a draw die in which the draw die is provided with a member that extends into the drawing passage to contact and shape interior surfaces of the channel member while the outer surfaces of the channel member are being shaped by outer forming surfaces of the draw die.
A difficulty that has been encountered in the past with such operations arises from varying, unbalanced, or laterally-directed components of generally longitudinal forces used to pull the channel member. The problem arises when the drawing force is transmitted through the member being drawn to that portion of the die that is disposed in contact with the interior surfaces of the channel member. Undesirable components of the force can result in loadings on the insert that cause it to snap off from the remainder of the apparatus.